I have two mandatory variable in my selection like vendor and customer.
my requirement is like that
" Either vendor or customer is mandatory, not both"
1> if we execute the query, and put both the value in selection screen and execute system should give above message and come back to that selection.
2> if we put both the field remain blank system should give same message.
3> if we give any one of them it should execute properly.
welcome on board ...
About your issue I would sugget to implement to implement an How to solution named "How to ... Verify the Variable Input" that works you Customer Exits.
The Document is available in http://service.sap.com/bi under Services & Implementation -> HOW TO... Guides -> Guide List SAP BW 2.x
If you cannot find the doc write me at firstname.lastname@example.org
Hope it helps